Long-term outcome in patients treated by intracoronary stenting with ticlopidine and aspirin, and deleterious prognostic role of unstable angina pectoris

A Cost-Effectiveness Analysis of a Hypothetical Catheter-Based Strategy for the Detection and Treatment of Vulnerable Coronary Plaques with Drug-Eluting Stents

AIM

Extensive efforts are underway to develop methods for the detection and treatment of vulnerable/high-risk coronary artery plaques. We utilized decision analysis to evaluate the hypothetical clinical benefits and cost-effectiveness of a catheter-based strategy.

METHODS AND RESULTS

Currently, stenotic coronary plaques are treated without regard to vulnerability. In a new strategy, vulnerable coronary plaques are detected with a catheter-based test and treated with a drug-eluting stent, regardless of degree of stenosis. A Markov-decision model was developed to compare the new strategy with current practice. Monte Carlo simulations were performed from a societal perspective, costs were converted to year 2003 U.S. dollars, and future costs and outcomes were discounted at 3%. Sensitivity analyses were performed to evaluate the effect of assumptions on variables such as the prevalence of vulnerable plaques and treatment effect. In 60-year-old male patients with coronary stenoses the new strategy would be less expensive and more effective than current practice (37,045 dollars vs 38,257 dollars and 10.23 vs 9.86 quality-adjusted life years (QALYs), respectively). The benefits of the new strategy were robust in sensitivity analyses (e.g., if the prevalence of vulnerable plaques in this patient group was 50% or more and the sensitivity and specificity of the new test were at least 0.80).

CONCLUSION

In selected patients with coronary artery stenosis, the detection of vulnerable plaques with a catheter-based test followed by their treatment with a drug-eluting stent could be a less expensive and more effective strategy than current practice. If applied to 1 million such patients in the United States undergoing catheterization, the new strategy would add 370,000 QALYs and save 1.2 billion dollars per year.

[Prognostic role of systemic hypertension and diabetes mellitus in patients with unstable angina undergoing coronary stenting]

BACKGROUND AND OBJECTIVES

The adverse effects of systemic hypertension and diabetes mellitus in coronary patients are well known, although their long-term prognostic influence on patients with unstable angina (UA) undergoing percutaneous coronary intervention (PCI) with coronary stenting is uncertain. The aim of this study was to determine the influence of these pathologies in this population at 3-year follow-up.

PATIENTS AND METHOD

We studied 279 consecutive patients with UA who underwent coronary stenting. 129 (46.2%) of them had hypertension and 60 (24.7%) had diabetes. Clinical follow-up was obtained in 92.14% after 3 years.

RESULTS

Although the need for new PCI at the target lesion was higher for patients with hypertension and diabetes (12.1 vs 8.4%; p=0.31, and 14.5 vs 8.6%; p=0.16, respectively), the differences were not significant with respect to the control groups. Multivariate analysis showed hypertension (OR=4.71; CI 95%, 1.01-42.2; p=0.04) and ejection fraction (OR=0.95; CI 95%, 0.91-0.99; p=0.03) to be predictors of mortality, and diabetes to be a predictor of myocardial infarction and infarction resulting in death (OR=3.01; CI 95%, 1.13-8.02; p=0.02, and OR=2.68; CI 95%, 1.03-6.95; p=0.04, respectively).

CONCLUSIONS

Hypertension was the only independent long-term predictor of mortality in our series of patients with UA who underwent coronary stenting. Diabetes was the only predictor of myocardial infarction or for the combined event of infarction and death. Risk of myocardial infarction was threefold as high in this diabetic patient population, and was the main cause of mortality.

Outcomes of patients presenting with acute coronary syndromes and negative Troponin-T

The aim of the study was to compare need for revascularization and clinical course between troponin-positive and troponin-negative patients with unstable angina pectoris defined as class IIIB according to Braunwald classification.

METHODS

The study group consisting of 104 patients was divided into troponin-positive (28 patients) and troponin-negative (76 patients) subgroups. Per study design all patients underwent coronary angiography. The subgroups were compared in regard to angiographic status and consequently the need for revascularization. Additionally, major adverse cardiac events (MACE) consisting of death, myocardial infarction, in-hospital revascularization during 30-days follow-up were assessed in subgroups.

RESULTS

In 58 (76%) patients with negative troponin test, the angiographically significant coronary artery stenosis was shown. Major adverse cardiac events were similar in both groups. Regardless of the initial TnT status, in both groups revascularizations (percutaneous or surgical) were performed with high frequency (89 versus 72%, P=NS).

CONCLUSION

In patients with unstable angina in class IIIB according to Braunwald classification, the negative cardiac troponin test did not exclude severe coronary artery disease, which in the majority of patients required revascularization without any additional non-invasive testing for ischemia. Therefore, we postulate that patients with clinically evident unstable angina (IIIB) should be referred to early invasive assessment despite negative troponin T screening.

Therapeutic adjuncts for immediate transfer to the catheterization laboratory in patients with acute coronary syndromes

Early coronary intervention in patients with non-ST-segment elevation myocardial infarction (MI) and unstable angina may be made safer and more efficacious with concomitant therapies, including glycoprotein IIb/IIIa inhibitors and low-molecular-weight heparins. Stent placement has been shown to improve procedural success and reduce major in-hospital complications when compared with balloon angioplasty alone in patients with unstable angina. However, unstable angina remains a major hazard for adverse coronary events in long-term follow-up after elective stent placement. The currently available glycoprotein IIb/IIIa inhibitors-eptifibatide, tirofiban, and abciximab--have each been shown to reduce ischemic events before percutaneous coronary intervention when administered to patients presenting with non-ST-segment elevation acute coronary syndromes in large clinical trials. The adjunctive role of low-molecular-weight heparins in this scenario has been largely unexplored. Enoxaparin, when given before angiography or percutaneous coronary intervention, has been shown to be superior to unfractionated heparin in preventing major coronary events. In this review, an algorithm for treatment of non-ST-segment elevation acute coronary syndromes is presented and the current role of these newer adjunctive pharmacotherapies is explored. In the future, combinations of these agents may prove to be most beneficial in patients undergoing early percutaneous coronary intervention.